Bis (2-hydroxy-alpha-methylbenzyl) benzenes



Patented Apr. 7, 1953 BIS(Z-HYDROXY-a-METHYLBENZYL) BENZENES Clarence L.Moyle, Clare, Mich., assigncr to The Dow Chemical Company, Midland,Mich., a corporation of Delaware No Drawing. Application February 18,1952, Serial No. 272,257

.1 Claims.

The present invention is concerned with thebis(2-hydroxy-a-methylbenzyl)benzenes of the formula wherein Zrepresents a member of the group consisting of the metaandpara-phenylene radicals and X represents a member of the groupconsisting of chlorine, methyl and hydrogen.

formula @Qon wherein the symbol -A represents a member of the groupconsisting of chlorine, methyl and hydrogen. The reaction, is carriedout in the presence of a dehydrohalogenation catalyst such as zincchloride. The reaction is somewhat exothermic and takes place smoothlyat the temperature range of from 80 to 160 C. in practice, it ispreferred to employ a molecular excess of the chlorophenol reactant.

in carrying out the reaction, the chlorophenol reactant and zincchloride catalyst are mixed together and the di(a-chloroethyl)benzeneadded portionwise thereto over a short period of time. The reactiontakes place smoothly with the production of the desired product and theevolution of hydrogen chloride of reaction. The addition is carried outat a temperature of from 80 to 120 C. and the temperature subsequentlyraised to from 1&0 to 160 C. for a short period of time t tocomplete'the reaction. Following the reaction, the desired product maybe separated by fractional distillation under reduced pressure.

in an alternative method, the bis(2-hydroxy-3,5-dichloro-a-methylbenzyl)benzenes may be 2 prepared by the directchlorination of the bis(2- hydroxy 5 chloro a methylbenzyhbenzeneswhereby one chlorine atom is substituted on each phenol ring ortho tothe hydroxyl group. In carrying out the chlorination, the bis(2-hydroxy-5-chloro-a-methylbenzyl)benzene is dispersed in a non-reactive solvent,such as carbon tetrachloride; and chlorine added portionwise theretountil two molecular equivalents thereof have been introduced into thereaction zone. The ad.- dition is carried out with stirring and at atemperature of from 20 to 40 C. Followingthe reaction, the desiredproduct may be separated by fractional distillation under reducedpressure.

The following examples illustrate the invention but are not to beconstrued as limiting.

EXAM LE 1 Bis(2-hydro;cy-5-chloro a-methylbenzyb benzene 180 grams (1.4moles) of 4-chlorophenol and 10 grams of anhydrous zinc chloride weremixed together and 40.6 grams (2 moles) of a mixed di-(a-chloroethyhbenzene product (boiling at -80 C. at 0.12-0.53 millimeterpressure and consisting essentially of percent of. the meta isomer and25 percent of the para isomer) was added portionwise thereto over aperiod of about 75' minutes." The addition was carried out with stirringand at a temperature of from sl to 101 C. Following the addition, thereaction mixture was heated for a short period of time at graduallyincreasing temperatures up to a temperature of 122 C. to complete thereaction. The crude reaction product was then diluted with 25milliliters of chlorobenzene and the resulting mixture washed withdilute aqueous hydrochloric acid. The washed product was thenfractionally distilled under reduced pressure to obtain a bis- 2'hydroxy-5-chloro-a-methylbenzyl)benzene product as a soft orange solidhaving a boiling range of from 235 to 255 C. at'3 millimeters pressure,a density of 1.20 at 25 C. and a chlorine content of 19.1 percent ascompared to a theoretical content of 18.4 percent.

EXAMPLE 2 Parabis(2-hydroa:y-5-chloro-a-vneihylbenzyl) benzene 257 grams(2 moles) of 4-chlorophenol and 20 grams of anhydrous zinc chloride weremixed together and 60.9 grams (3 moles) of para-bismchloroethyhbenzene(boiling at ll0-116 C. at 2.8-6.4 millimeters pressure) addedportiomvise thereto over a period of 45 minutes. The addition wascarried out with stirring and at a temperature of from 81 to 95 C.Following the addition, the reaction mixture was heated over a period of15 minutes at gradually increasing temperatures up to a temperature of155 C. to complete the reaction. The reaction mixture was then cooled to130 C. and diluted with 50 milliliters of chlorobenzene. The resultingmixture was then successively washed with dilute aqueous hydrochloricacid, and water, and thereafter fractionally distilled under reducedpressure to separate a para-bis(2-hydroxy-5-chloroa-methylbenzyDbenzeneproduct as a viscous orange oil boiling at from 267 -276 C. at 2millimeters pressure.

EXAMPLE 3 Bis(2 hydroxy 5 chZoro-3-methyl-a-methylbeneyl) benzene 32.4grams (0.3 mole) of .4-chloro-o-cresol and 2.7 grams of Zinc chloridewere mixed together and 20.3 grams (0.5 mole) of thedim-chloroethyDbenzene product described in Example added portionwisethereto at gradually increasing temperatures up to a temperature of 98C. The addition Was carried out with stirrin and over a period of 2hours. The reaction mixture was set aside for 48 hours and thereafterWashed with water. The washed mixture was then diluted with a methanolsolution of dilute aqueous EXAMPLE 4 Bz's(2 hydroxy 3,5 dichloro amethylbenzyl) benzene 20 grams (0.05 mole) of the bis(2-hydroxy-5-chloro-amethylbenzyl)benzene product of EX- ample 1, was dissolved in 50milliliters of carbon tetrachloride and the resulting mixture placed ina flask equipped with a tirrer, reflux condenser and a chlorine inlet.Chlorine gas was thereafter introduced into this mixture at roomtemperature over a period of one and one-half hours and until no furtheradditional amounts of chlorine were absorbed by the mixture. The carbontetra- 2,ca4,29"r h Y chloride was then removed by evaporation and theresulting product fractionally distilled under reduced pressure toobtain a bis(2-hydroxy-3,5- dichloro-a-methylbenzyl)benzene product as aviscous orange oil having a boiling range of from 275 to 286 C. at 5millimeters pressure and a density of 1.31 at 30 C.

The di(e-chloroethyl)benzenes employed as starting materials may beprepared by reacting metaor para-divinyl benzene or a mixture of saidisomers with hydrochloric acid, to add one chlorine atom on the alphacarbon atom and one hydrogen atom on the beta carbon atom of each vinylgroup. In carrying out the reaction, two molecular proportions of thehydrochloric acid is added portionwise to one molecular proportion ofthe divinyl benzene reactant with stirring. The reaction is somewhatexothermic and takes place smoothly at from about 15 to C. Following thereaction, the desired product may be separated by conventional methods.

I claim:

1. A bis(2-hydroxy-a-methylbenzyl)benzene of the formula REFERENCESCITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Taylor et al Mar. 16, 1943 Number

1. A BIS(2HYDROXY-A-METHYLBENZYL) BENZENE OF THE FORMULA